/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * @author Vladimir N. Molotkov, Stepan M. Mishura
 */

package org.apache.harmony.security.asn1;

import java.io.IOException;

/**
 * This class represents ASN.1 Boolean type.
 * 
 * @see http://asn1.elibel.tm.fr/en/standards/index.htm
 */

public class ASN1Boolean extends ASN1Primitive {

	// default implementation
	private static final ASN1Boolean ASN1 = new ASN1Boolean();

	/**
	 * Returns ASN.1 Boolean type default implementation
	 * 
	 * The default implementation works with encoding that is represented as
	 * Boolean object.
	 * 
	 * @return ASN.1 Boolean type default implementation
	 */
	public static ASN1Boolean getInstance() {
		return ASN1;
	}

	/**
	 * Constructs ASN.1 Boolean type
	 * 
	 * The constructor is provided for inheritance purposes when there is a need
	 * to create a custom ASN.1 Boolean type. To get a default implementation it
	 * is recommended to use getInstance() method.
	 */
	public ASN1Boolean() {
		super(TAG_BOOLEAN);
	}

	//
	//
	// Decode
	//
	//

	@Override
	public Object decode(BerInputStream in) throws IOException {
		in.readBoolean();

		if (in.isVerify) {
			return null;
		}
		return getDecodedObject(in);
	}

	@Override
	public void encodeContent(BerOutputStream out) {
		out.encodeBoolean();
	}

	//
	//
	// Encode
	//
	//

	/**
	 * Extracts Boolean object from BER input stream.
	 * 
	 * @param in
	 *            - BER input stream
	 * @return java.lang.Boolean object
	 */
	@Override
	public Object getDecodedObject(BerInputStream in) throws IOException {
		if (in.buffer[in.contentOffset] == 0) {
			return Boolean.FALSE;
		}
		return Boolean.TRUE;
	}

	@Override
	public void setEncodingContent(BerOutputStream out) {
		out.length = 1;
	}
}